Three shark attacks in two days have residents along California shores north of Santa Barbara on edge. A surfer and two kayak fishermen have been attacked since Thursday near Vandenburg Air Force Base, GrindTV reports.

On Thursday, three beaches along the base were closed through the weekend after the 28-year-old surfer was attacked. The man, whose name hasn’t been identified, was bitten on the knee while surfing in an area known as Jacks Point, according to the Associated Press. Sgt. Tyrona Lawson, a base spokeswoman, said the man was hospitalized but didn’t elaborate on his condition.

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That attack happened around 5:30 p.m. Thursday, the Associated Press reports. Witnesses said the shark was 10 to 12 feet.

The first attack prompted Vandenberg Air Force Base to close Surf, Wall and Minuteman beaches until 4 p.m. Sunday, the L.A. Times reports.

On Friday, two kayak fishers were attacked in separate incidents, though Vandenburg only acknowledged the Thursday attack on its website.

A group of kayakers were ambushed by a shark and got a glimpse of what one man said was a 20-foot great white. Vince Culliver, a fireman with the Air Force Base, told GrindTV that his friend was flipped out of his kayak by the animal.

“I was waiting for Ryan to pop up,” Culliver said. “And the shark still had his kayak in its mouth.”

Culliver was able to help his friend aboard his own kayak and both men made it to safety.

Earlier in the day, another kayaker was also knocked off of his boat, witnesses told GridTV. In both attacks, the men’s kayaks were badly damaged.

It is unclear if all three men were attacked by the same shark.

These are the fifth shark attacks to happen near the base in October since 2010, according to GrindTV. Two were fatal: In 2010, an attack killed Lucas Ransam, a 19-year-old University of California at Santa Barbara student who was bodyboarding. In 2012, 29-year-old Francisco Solorio was killed while surfing.

Vandenberg is a missile- and space-launch site about 130 miles northwest of Los Angeles, according to the Associated Press.